As is often said of cameras, "The best one is the one you have with you." For a telescope, that means the one that's small enough to roll with you, wherever you roam. Whether you're on a safari in the Outback, or camped out in a studio apartment in the city, small is beautiful as long as your view through the eyepiece is huge.

You stand a better chance of seeing the deep sights of the universe by taking a small telescope to a very-dark-sky location than by keeping a not-very-portable larger scope at home under light-polluted, smoggy skies.

Whether you travel or are simply storage-space-challenged (or both), our editors have selected the best "grab-and-go" telescopes for you:

Now, Celestron has come to market with a spotting scope that is excellent for "grab-and-go" astronomy as well. The Regal M2 100ED can pull a lifetime of visual memories into its 19.25-inch (48.9 centimeters), 4.6s-lb. (2.1 kg) frame. The M2's body is cast of lightweight magnesium alloy, stronger than aluminum. And its detented, rotating tripod mount lets you set the whole instrument at the most comfortable viewing angle.

Optically, spotting scopes tend to be like one half of binoculars on steroids. The M2’s 100mm (4-inch) aperture is large, even for a spotting scope. But it's perfect as an astronomical refractor that's still compact enough to take with you. That big front objective lens is cast of exceptional quality "ED" glass. The "ED" stands for "extra-low dispersion," which gives you the precise hues of planets, with reduced chromatic aberration (false colors) around the edges. These optics also give you tack-sharp stars and a deep contrast range to pick out fine detail in nebulas.

But that big lens is heavy compared to the rest of the rig. So Celestron has thoughtfully provided a balance plate. This keeps the scope's mass even atop a tripod. You attach this plate to your tripod (purchased separately) and slide the scope along the slotted portion of the plate until the balance feels right. Then, simply tighten the locking ring. Two cautionary notes: 1) The slide may not give enough clearance for tripods with quick-release blocks. 2) Be careful when rotating the scope as the slide can dig into the rubber coating on the tube and leave an ugly scratch.

The Celestron M2 100ED rotates to give you the most comfortable viewing angle. A dial-out eyecup tames stray light and sets up optimal distance for eyeglass wearers.

At the back of the scope, unscrew the protective guard to reveal the eyepiece. It has a twist-out eyecup. This works to block out extraneous light. It’s especially important for eyeglass wearers. And if you're nearsighted, this helps you dial in the right amount of eye-relief distance for best focus. The M2's stock eyepiece is not specifically designed for astronomy. But the scope is designed to accommodate standard 1.25-inch astronomical eyepieces. You'll need to purchase these separately.

Zoom and focus are fast. You can continuously vary the magnification from 22x up to 67x. The smooth dual focuser has concentric coarse and fine adjustment knobs.

Up front, near the 100mm (4-inch) objective lens, you'll find a slide-out sun hood guarding the optics from unwanted light and protecting it from water. As temperatures change at night, that hood does double duty as a dew shield.

Astronomers don't come out only at night. If you're a birder or a people-watcher (think: sports) you'll like the sharp resolution and excellent color accuracy of this instrument. I was able to read a typical street sign from more than a mile away across a river.

This spotter hasn't yet caught on with many long-gun shooting clubs, but we think it might. The M2's maximum zoom of 67x can resolve small-caliber marks on faraway targets. (For example, .22-caliber ammo hits at 175 yards, or 160 meters).

Astronomical telescopes tend to be delicate. This one, because it's designed as a spotting scope, is more rugged. It's rubberized for shock and sealed for water resistance. The nitrogen-purged tube is less likely to fog up internally, and will form less dew on its optics, than a similarly size refractor telescope meant for the astronomy-only user.

You will need to buy an appropriate tripod; make sure it slides down to short length for travel. It needs to be fairly heavy so it doesn't wiggle in the wind, jiggling your view. And you'll want to pay attention to the type of mount; we recommend a paddle-handle locking altitude/azimuth rig.

Are you a "digiscoper?" That's someone who shoots their digital camera through a spotting scope. Birders and other animal-watchers often like to do this. The Regal M2 is compatible with a large number of point-and-shoot cameras. Celestron offers a universal camera adapter to facilitate such "afocal" photography (purchased separately). As with any digiscope setup, you do have to be careful about vignetting; that black area surrounding a circular image in the center of your picture. You can also attach your SLR camera to the M2 using the included T-adapter step ring, added to the eyepiece.

Wrap your Celestron M2 100ED in its protective case and get out there, day or night.

The M2 comes with a water-resistant soft case you can sling over your shoulder. It is light green ballistic nylon on the outside with a layer of shock-foam padding inside. You can operate the scope in this case but it isn't as well designed for accessibility as the case accompanying the Levenhuk Blaze spotting scope (reviewed below).

Our Editors' Choice of last year, the Pentax PF-80ED-A, is still a good choice. But Celestron's Regal M2 100ED boasts 125 percent larger aperture, balances better on your tripod and costs about $300 less.

Orion's StarMax 90 folds the light-path to give you big performance in a small package. It's Maksutov-Cassegrain optical design accepts light through a front objective, bounces it off a curved primary mirror at the back, to a secondary mirror mounted on the front objective, then out through a hole in the primary, through the eyepiece. Brilliant!

Is your table waiting? Not the first question you expect to hear when talking about astronomy. But that's something to consider when considering Orion's StarMax 90. It's a compact, powerful and — at $200 — very cost-effective portable telescope. But, yes, it needs a flat platform on which to perch. Orion calls it a "tabletop go-scope." Just know before you go if there will be a flat surface available for you under the sky.

At 6.5 lbs. (3 kg), this system is light enough to take on the road. Just be aware that the irregular shape of the base takes up more space than most other portable telescope configurations.

The optics come all ready to use. But, to give them something upon which to rock, you'll have to assemble the mount. After a few minutes of woodwork with simple tools provided, you'll have an up-down/left-right ("altitude / azimuth") base ready to observe. All you need, then, is that table to set it on.

Alternatively, you can mount the whole affair (optical tube with finder + "AltAz" base) on a sturdy tripod; there's a threaded collar on the bottom. Just make sure your 'pod can handle the weight of the pivoting/rocking base. (Orion offers a $300 bundle: telescope and tripod.) And figure that the tripod will add at least 2.5 lbs. (1.1 kg), for a total weight of about 9 lbs (4 kg). That's fine for car camping, but probably more than you want to carry in a backpack.

De-couple the StarMax 90 from its table-top base and you can mount it on a standard camera tripod. Just remember that if you insert the eyepiece directly into the optical tube, the image will be inverted. [Shown with option finder-scope, available at extra cost, replacing the included EZ Finder II.]

If you already own a camera tripod you can remove the StarMax optical tube from its wood mount and fit it to the head of your 'pod's swiveling head. Now you have the makings of a "spotting scope" (like those reviewed above). For true spotting scope performance, you would need to buy a separate "correct image" diagonal to flip the view upright and flop it so as not to appear reversed (like a mirror image). Just make sure your tripod is steady. The higher the magnification you use, the more your celestial image will dance around in the eyepiece, unless the base of the telescope is stable.

Orion's StarMax 90 folds the light-path to give you big performance in a small package. It's Maksutov-Cassegrain optical design accepts light through a front objective, bounces it off a curved primary mirror at the back, to a secondary mirror mounted on the front objective, then out through a hole in the primary, through the eyepiece. Brilliant!

The StarMax 90 doesn't come with a tubular finder scope, just a small red-dot finder. But it's perfectly adequate for centering most targets and its tiny size helps keep this whole rig transportable.

Surprisingly, Orion gives you three eyepieces: 25mm, 10mm and 6.3mm. Most consumer telescopes come with only two. The low-power 25mm drives this scope to 50x. The 10mm — which would be considered high-power by other brands — takes it to 125x. The extra-high-power 6.2mm squeezes 198x out of this small telescope, just barely under its usable limit. But you'll need a very bright object — Mars, Jupiter or Saturn at opposition, for example — to actually see anything worthwhile. In general, the StarMax 90 is best for the moon and planets, but it can also pull in some higher surface-brightness galaxies and star clusters under dark skies.

If you have a camera — SLR, DSLR or mirrorless — you could adapt this optical tube as a long-range telephoto system. You would need so-called "T-adapter," specific to your camera's lens mount. And you'd have to get used to framing a flipped/flopped image. This will work best for daytime terrestrial shots. At night, you can shoot the moon (and, probably, only the moon) because it's bright enough for short exposures. But stars and planets will swim across a long exposure, giving you an artistic histogram of Earth's rotation; probably not what you want.

Telescopes are more about gathering light than they are about magnification. Once gathered, the art is in not letting photons bounce around willy-nilly inside the tube, You also don't want to lose them to diffusion into badly cast lenses. Orion's optical quality shines here: This small StarMax presents noticeably more contrast than comparably priced refractors and reflectors. It achieves this with well-coated optics and by folding the light path, using the clever and cost-effective "Maksutov-Cassegrain" design.

In the box, Orion includes a digital download for Starry Night Special Edition software. I believe it's a good tool for planning your observing targets and for fun learning about the cosmos. But — full disclosure — I contributed to the development of Starry Night software.

Imagine a table for two (or more) under the stars. Just add the StarMax 90, and you're ready to make memories.

Country or city, day or night, Levenhuk's Skyline Travel 80 is a flexible, portable, inexpensive telescopic companion. The optical tube and its accessories are made of light-duty plastic to save cost and weight. Treat it gently and it will do its job. But don't expect the Skyline to stand up to years of hard use.

Levenhuk's Skyline Travel 80 gives you a spotting scope-style refractor at a fraction of the cost of the typical spotting scope. Such instruments are commonly used by birders, target shooters and other outdoor sports-folk; less often, by amateur astronomers. But it's nice to have one telescope that serves a lot of different uses. Tuck it, along with its aluminum tripod, in its (provided) nylon transport bag and get out there — all for less than $150.

The Skyline Travel 80 refractor and its long-legged tripod comes in a tough nylon carry bag with handles and a shoulder strap. The rig is lightweight and highly portable. It sets up and breaks down quickly. But the telescope and its accessories aren't very durable. And the optical quality, while acceptable, cannot compete with more expensive spotting scopes.

High-end spotting scopes, from makers such as Nikon and Kowa, are often priced above $1,500. A top-of-the-line Swarovski spotting scope can cost double that. So, what don't you get with Levenhuk's Skyline Travel 80 that you would if you spent 20 times as much money?

Simply put, your images will not be as sharp, as bright, as flat, or as accurate in color, and they will have false-color outlines on the edges of objects. Why does it cost so much to get a better image?

When light passes through a lens, it bends. The shorter the wavelength (more toward blue and violet), the steeper the bending. As the colors are split out of white light, they "land" in different places. Your eye can be in only one place along the path. The result: You see blurry colored edges on objects. This visible and annoying break-up is called "chromatic aberration." Every refractor telescope exhibits some degree of this color distortion.

One way of counteracting this effect is to make the telescope very long. Another is to place additional lenses in the light-path to compensate. And a third way is to cast the lenses of very pure materials. Inexpensive refractors — like the Skyline Travel 80 — can't take advantage of any of these strategies. So, expect to see some color deviation and "fringing."

But the spectral distortion doesn't have to ruin your observing. Under the canopy of night, this Skyline is well-suited to view the moon at any phase except the four or so nights around the full moon (when the amount of sunlight reflected off the lunar surface makes it just too bright). You can see color on the brightest planets, but not a whole lot of surface details or cloud-forms. Under very dark skies — away from artificial lights and on moonless nights — the Skyline will pick up the brightest (nearest) few galaxies and star clusters. But it's neither optically fast enough nor powerful enough in magnification to look very far into deep space.

Levenhuk's Skyline 80 comes two Kellner eyepieces (9mm and 25mm) and a 3x Barlow lens to give four different magnifications. A mirror diagonal provides an upright, non-reversed image for daytime viewing. At night, a 5 x 20 finder-scope helps center-up celestial targets. And a built-in compass helps you find them. Focus knobs on either side let you dial in your image with left of right hand. The Skyline says "Zoom & Joy" on its optical tube, but that's a marketing tagline; It does not actually zoom.

Expensive upper-tier spotting scopes often come with a zoom eyepiece, to give varying magnifications. The Skyline 80 does not zoom, but it does give you configurations to achieve four different magnifications: The kit comes with 3x Barlow lens and two Kellner eyepieces: a high power (9mm) and a low power (25mm). Magnification tops out (theoretically) at 132x, but because you're stacking "slow speed" lenses, your image won't be very bright.

Younger astronomers will appreciate the Skyline's simplicity and intuitive operation. The included diagonal gives you an erect, intuitive view: "right side up and not mirror image." There's a built-in compass to help you orient. You'll also get a legitimate 5 x 20 finder-scope to help center-up your celestial target — most comparable scopes have only a rudimentary "red-dot" finder. You will, however, have to learn how to align the finder to the main telescope (it's easy to do).

Best for Urban Astronomers:

Levenhuk Strike 90 Plus

Refractor on a tripod with counterweight

Cost-effective manual telescope for rooftop skywatching

City skies are full of light, and urban astronomers have two choices: Get a city-strong telescope to carry up to the roof, or get a highly portable scope and get out of town. Levenhuk's Strike 90 Plus Refractor gives you both, plus a nice bag to carry it in on your adventures. Add a "sky-glow" filter to your eyepiece to give you a fighting chance of seeing more than just the moon when observing from cities.

If you live in a city, your rooftop can make a surprisingly good observatory. Levenhuk's Strike 90 is a solid, and surprisingly tough, performer for urban astronomers. This short-tube refractor's design makes it compact enough to travel. The 3.5-inch (90 mm) aperture gathers enough light for you to observe plenty of deep-sky objects under dark skies. But in the city or suburbs, make sure to add a light-pollution ("sky-glow") filter.

This inexpensive scope is city-sturdy. The tripod is an animal, in a good way. Sturdy 1.14-inch (29 mm), round, steel legs extend the mount's platform height from 27 inches (69 mm) up to nearly 48 inches (121 mm). Three large rubber feet spin back to reveal spikes for poking into terrain, even if frozen. This tripod is very strong. To test it, I stood on top of the tripod's platform; I weigh 145 lbs. (66 kg), and I felt perfectly supported on this platform. Though why, exactly, I seem to want to do this is a mystery.

The triangular accessory platform has five cutouts for eyepieces. But it's not a tray; having no lip, it won't restrain any other items. And it can easily get knocked off, especially in cold night air as the metal shrinks and comes loose from the tripod. Your delicate eyepieces can come crashing down. Do be careful.

This Levenhuk's unusual altitude-azimuth mount shares heritage with the one on a previous telescope in this series, the smaller and lighter Strike 50. But the Strike 90 sports an oddly positioned counterweight off to the starboard side (right side when at the eyepiece end). It works; it just takes some getting used to. There's an awkward, inevitable collision waiting to happen: At some attitudes, the counterweight stalk will knock the azimuth slow-motion control knob off. You might not hear it fall and roll away in the dark.

The 3.5-inch (90 mm) primary lens is well-cast and coated. The tube's wall thickness has enough heft that it should equilibrate to temperature smoothly. There won't be any need to internally align or calibrate this scope because it's a refractor. Levenhuk claims a maximum useful power of 165x. That's a bit optimistic; with the highest-power eyepiece included in the box, you'll get about 100x.

But astronomy is really much more about brightness and contrast than magnification. And the simplicity of this refractor's optical path ensures that few celestial photons will go unused. That's important, because your eyes can never get fully dark-adapted in the city.

Unique among scopes of this class, the Strike 90 comes with a zoom eyepiece. This gives you a continuous range-change from a medium-wide low power (16 mm) up to a higher power (6.8 mm). Purists will complain that such a compound lens must let less light in. They're not wrong, but the convenience can't be beat, especially for young observers in a hurry. And for daytime, terrestrial use, the zoom lets you frame targets on Earth.

The mirror diagonal that comes with Levenhuk's Strike 90 Plus Refractor will let you focus on targets on Earth. But if you're in a city, add a "sky-glow" filter to your eyepiece to observe astronomical objects other than the moon.

But the Strike 90 doesn't come with a light-pollution filter. For use under or near city lights, you will want to get a "sky-glow" filter such as Orion's UltraBlock or Celestron's UHC/LPR. These devices are tuned to reduce the wavelengths produced by the most common types of artificial lighting.

Some filters are broadband, so they let most of the visible spectrum through, minus the city lights. Others are narrow-band, so they limit the light the observer sees to the emissions of glowing gas nebulas. Neither of these devices will brighten the image you see through the scope (in fact they slightly reduce it), but both will enhance the contrast, making it easier for your eye to see comet tails, the fuzzy remains of exploded stars or the blush of billions of stars defining a galaxy.

To take your telescope on tour — even if you're just going up to the roof or out on the fire escape — you'll need a bag. Levenhuk gets extra star-points for including a rugged-nylon carry-case for the whole rig (with the bizarre model name "Zongo 20"). It's fairly tough and puncture-resistant, though we could wish for more shock foam in the lining. There's no such thing as too much padding for an optical device in a soft case.

You'll be surprised at what you can see deep in the sky from deep in the city. Just be prepared to explain to local law enforcement that you're gazing at the stars, not at the neighbors.

The Orion ShortTube 80-A is like the Toyota Camry of telescopes. It's an economy choice that can get you almost anywhere in relative comfort. It's well built, with few indulgences. And there are many, many of them out there.

This is the most cost-effective "grab and go" compact telescope: Decent aperture, fairly tough, lightweight and very good optics.

The "A" stands for "astronomy." While you certainly can (and should!) use this excellent scope for animal watching or sports, Orion has specially coated the optics, and given this model a precisely engineered focuser mechanism, for observing the sky. The 80mm medium-fast f/5 optical path pulls in wide star-fields. You'll want to invest in neutral density (gray) "Moon Filter" to watch Earth's companion, which will be too bright in the unfiltered eyepiece.

You'll need a few other extras. Start by selecting a good camera-style tripod. Orion recommends its heavy-duty model tripod and head (about $160). This tripod folds down to a length of 34 inches (86 cm), which is not quite as small as we would like for travel. It is, however, wonderfully sturdy.

The Orion 80-A comes with a 90-degree mirror "star" diagonal for astronomy. If you also intend to use your Orion ShortTube 80-A for daytime terrestrial viewing (animals, people, boats, etc.), be sure to configure it with Orion's "correct image diagonal" ($57) and "correct image finder scope" ($100). These will show you the world as it is, rather than reversed left to right or upside down, or both, as with some types of astronomical telescopes. If you'd like help selecting accessories, Orion's Live Chat messaging app is brilliant. We've found that being in near real-time contact with a very knowledgeable customer service rep — one who is not all about the "hard sell" — is very reassuring.

Depending on the tripod you pick, your ShortTube 80 rig will weigh about 9 to 14 lbs. (4 to 6 kg). But it could be small enough to fit into your carry-on bag, so it won't tip your checked baggage into the extra-fee zone. We know a couple of world-class eclipse chasers whose go-to "grab and go" is the Orion ShortTube 80-A. Why not join them out there?

A Computerized Choice:

Up to this point, our compact "go scope" choices have all been refractors. But there's another way to squash down the photon-gathering power of a larger telescope into a smaller size: Fold the light path.

Celestron's NexStar 4SE is a hybrid of reflector and refractor — a "catadioptric" telescope. Specifically, it's a Maksutov-Cassegrain, a brilliant design that reduces a few of the inherent problems of both refractors (color anomalies) and reflectors (deviation from flatness). On the other hand, having both lenses and mirrors in the mix steals more than a few photons from the star party.

The most fully featured "Go-To" portable we tested, this Maksutov Cassegrain hybrid telescope aligns easil;y to the sky and tracks your celestial targets.

You look through a hole in the primary mirror and out through the front "corrector plate," so the 4SE can be used as a daytime spotting scope. Just make sure you get an "erect image" diagonal for your eyepiece (and maybe an "image erecting" finder scope). It's a little clunky, but it works. With an appropriate adapter, it will work beautifully as a telephoto lens for your DSLR or mirrorless camera.

To make a compact telescope, optics engineers are compelled to reduce the aperture. But, at just over 4 inches (10 cm), the NexStar 4SE's radiation-reaping opening isn't tiny.

The 4SE is the only one of our "travelers' scopes" to carry an onboard computer, Celestron's battle-tested SkyAlign system. It's not a fully automated setup, but it's not hard to get the scope and mount aligned and tracking on the sky. Then, you can take advantage of SkyAlign's 40,000-object database. Theoretically, your view won't rise to the level of the more expensive "Hobbyist and Learner" models reviewed elsewhere on Space.com. But you might find yourself in a faraway dark-sky location to which you could not have transported a bigger telescope, so you might end up with a more memorable experience, thanks to the smaller telescope.

Don't have much to spend? Have hardly any room? There's still a solution: At the opposite end of the cost curve from the superb Celestron Regal M2 100ED, you'll find the economic Celestron TravelScope 60 NPF. Everything about this package is small; yes, unfortunately, that means the telescope's 2.36-inch (6 cm) aperture is a bit puny. But when fully rigged, it can still manage 140x magnification.

At an almost unbelievably low price, this mini-refractor is ready to travel in it's custom backpack with included tripod, eyepieces, finder-scope, flashlight and compass. Although the aperture is small, you'll get satisfactory night sky and daytime Earth views.

This little spotting-scope-style refractor comes in its own backpack. It's ready to travel: You get a collapsible tripod, a finder scope, two eyepieces (20 mm and 8 mm), a lunar filter (a must!), an image-erecting diagonal (a must!), a 3x Barlow lens "supercharger," a compass and a mini LED flashlight on a carabiner. You even get a free download of a National Parks guidebook. That's a whole lot of instrument for less than $85.

The whole kit, including its backpack, weighs only 3.8 lbs. (1.7 kg). Yes, everything about this kit, including the price, is lightweight. Yes, the thin aluminum tripod trembles in the wind. Yes, the aperture is small and consequently light-limited. No, the lenses and coatings are not laboratory grade. But all the essentials are here. And, if your TravelScope 60 NPF gets damaged out there in the wild, the loss will be more of a "Darn it" than an "Oh, $#@*!" moment.

The TravelScope is also a great starter scope for kids. You and your child could each be out there enjoying the sky or nature in the daytime. And you'd each have an instrument of your own. No need to worry about junior damaging or dropping your more sophisticated (expensive) instrument.